National security adviser Jake Sullivan on Sunday said that he cannot know for sure what will happen in Ukraine, but described how a potential Russian invasion would play out if it were to happen. 

"If there is a military invasion of Ukraine by Russia, it's likely to begin with a significant barrage of missiles and bomb attacks," Sullivan said. "Those are never as precise as any army would like them to be, and we don't even know how precise the Russian army would like them to be, so innocent civilians could be killed regardless of their nationality."


Jake Sullivan

White House national security adviser Jake Sullivan speaks during the daily briefing at the White House in Washington, Monday, Aug. 23, 2021. (AP Photo/Susan Walsh)

During an interview on CNN's "State of the Union," Sullivan continued by predicting there would be an "onslaught of a ground force moving across the Ukrainian frontier" following the bomb attacks if they occur, adding that civilians could get caught in the crossfire if this invasion takes place.

"We will defend NATO's territory," Sullivan said. "We will impose costs on Russia and we will ensure that we emerge from this as the West stronger, more determined, more purposeful than we have been in 30 years, and that Russia ultimately suffers a significant strategic cost for military action."

Sullivan said the Biden administration could not "perfectly predict" which day Russia would invade Ukraine, but said it could begin "any day now," stating that the way Russia has "built up their forces" and "the way they have maneuvered things in place makes it a distinct possibility that there will be major military action very soon."

Pentagon John Kirby

Pentagon spokesman John Kirby speaks during a briefing Thursday, Feb. 3, 2022. (AP Photo/Andrew Harnik)

Sullivan also reiterated a warning from the Biden administration to American citizens in Ukraine, telling them to leave Ukraine "immediately" and that there will not be a military evacuation. The State Department on Saturday said Americans should escape through Poland. 

Earlier this morning, Pentagon press secretary John Kirby told "Fox News Sunday" that intelligence shows that Russia could stage an invasion "any day now," if not sooner. He also said the U.S. will not impose sanctions against Russia before any potential invasion of Ukraine, adding that threatening sanctions has a "deterrent effect" that would be lost once sanctions are issued.


"If it's a deterrent and you use it before the aggression is made or the transgression is made, then you lose your deterrent effect," Kirby said. "If you punish somebody for something that they haven't done yet, then they might as well just go ahead and do it. So we believe there's a deterrent effect by keeping them in reserve and we have been very clear with the international community and with Mr. Putin about the severity of the economic consequences that he could face."

Fox News' Ronn Blitzer contributed to this report.